Seismic loadcases
Once the Seismic Wizard has been run the loadcases required to be applied to the structure can be generated.
Equivalent Lateral Force (ELF) Loadcases
If an Equivalent Lateral Force (ELF) analysis procedure was selected in the Wizard, the load is applied to the structure at each level as determined for the relevant direction - loadcases being created as follows:
For structures with no torsion
- Seismic Dir1 - loadcase type Seismic
- Seismic Dir2 - loadcase type Seismic
For all other structures:
- Seismic Dir1 - loadcase type Seismic
- Seismic Dir2 - loadcase type Seismic
- Seismic Torsion - loadcase type Seismic
+ and - factors are applied in the combinations to achieve the possible options - +Dir, -Dir, +torsion and -torsion.
Response Spectrum Analysis (RSA) Loadcases
If a response spectrum analysis procedure was selected in the Wizard, the loadcases are created as follows:
For structures with no torsion
- Seismic Dir1 - loadcase type Seismic RSA
- Seismic Dir2 - loadcase type Seismic RSA
For all other structures:
- Seismic Dir1 - loadcase type Seismic RSA
- Seismic Dir2 - loadcase type Seismic RSA
- Seismic Torsion - loadcase type Seismic RSA
Enveloping is used in the combinations to achieve the possible options - +Dir, -Dir, +torsion and -torsion.